(1) One of the evil spirits of traditional Jewish and Christian belief
(2) Someone extremely diligent or skillful
"He worked like a demon to finish the job on time"
"She's a demon at math"
(3) A cruel wicked and inhuman person
- daemon, dæmon (these spellings are generally only found for the senses of inner spirit and divinity of Greek mythology)
- An evil spirit.
- A fallen angel or Satanic divinity; a false god.
- One’s inner spirit or genius, a daimon.
- A spirit or lesser divinity between men and gods.
- A foible; a flaw in a person’s character.
- The demon of stupidity haunts me whenever I open my mouth.
- Someone of remarkable or diabolical energy or ability.
- He’s a demon at the card tables.